Entry & progression
The QMED exam is drawn from a subject matrix at 46 CFR 12.505. The subject areas are common; which of them you are examined in depends on the rating you are going for.
The subject areas
| Subject area | What it is really asking |
|---|---|
| General | The engine department, its organisation, its language, its basic principles |
| Electrical | Generation, distribution, motors, switchboards, safe isolation |
| Safety and environmental protection | Working safely below, and not putting oil over the side |
| Shipboard systems | Fuel, lube oil, cooling, bilge and ballast, compressed air, pumps |
| Steam propulsion | Boilers, feed systems, steam plant operation |
| Motor propulsion | Diesel engines and their supporting systems |
CAUTION — Read the matrix itself before you build a study plan The exact subjects examined for each rating are set by 46 CFR 12.505 and the NMC's current examination content. This lesson gives you the shape of it, not the cells. Do not plan six months of study off a course page — pull 12.505 and the NMC's current guidance for the rating you are seeking, and build the plan from that.
Steam is not optional trivia
Yacht engineers look at steam propulsion and assume it is a museum piece. It is not there for the ratings that do not need it — but it is squarely there for the Boiler Technician/Watertender, and the physics of boilers, feed water and combustion does not stop mattering just because your propulsion is diesel. Any yacht with an oil-fired boiler for the hotel load has a watertender's problem waiting for it.
What the subject areas mean in the metal
Do not learn these as exam headings. Learn them as the plant you stand a watch on.
- Electrical is why the generator will not take load, why the breaker tripped, and why you lock off before you open the box.
- Shipboard systems is why the purifier keeps shearing, where the air goes when you start the main, and which valve you close before you pull the strainer.
- Safety and environmental protection is the oily water separator, the bilge, and the reason nobody opens a tank without a permit.
- Motor propulsion is the diesel cycle, the fuel injection, the turbocharger, the cooling, the exhaust — and the sound it makes when it is unhappy.
Study the plant you are standing on
The most efficient study any candidate can do is on his own boat, on watch, with the manuals open. Trace every system end to end until you can draw it on the back of an envelope: where the fuel comes in, what cleans it, what pumps it, where it goes, what happens to what comes back. Do the same for lube oil, for cooling, for bilge, for starting air, for the electrical distribution.
A candidate who can draw those six diagrams from memory will pass a written examination on any plant in the world, because the examination is only testing whether he understands what he has been looking at. And the same six diagrams are what make you useful at three in the morning when the alarm goes and nobody has a manual open.